 = k + n - 2 + T (c1(TVK)(A) - |K| - 1) + E |KK|. 
In the sums \(\sum _{\alpha E \beta }\) , we take \(E\)  to be the set of undirected edges.


Follows from standard dimension counting, cf. [1]}. The second equality uses the Euler characteristic of the tree.
